// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef CONTENT_COMMON_HOST_SHARED_BITMAP_MANAGER_H_
#define CONTENT_COMMON_HOST_SHARED_BITMAP_MANAGER_H_

#include <stddef.h>

#include <map>
#include <memory>
#include <set>

#include "base/containers/hash_tables.h"
#include "base/hash.h"
#include "base/macros.h"
#include "base/memory/ref_counted.h"
#include "base/memory/shared_memory.h"
#include "base/synchronization/lock.h"
#include "base/trace_event/memory_dump_provider.h"
#include "cc/resources/shared_bitmap_manager.h"
#include "content/common/content_export.h"

namespace BASE_HASH_NAMESPACE {
template <>
struct hash<cc::SharedBitmapId> {
    size_t operator()(const cc::SharedBitmapId& id) const
    {
        return base::Hash(reinterpret_cast<const char*>(id.name), sizeof(id.name));
    }
};
} // namespace BASE_HASH_NAMESPACE

namespace content {
class BitmapData;
class HostSharedBitmapManager;

class CONTENT_EXPORT HostSharedBitmapManagerClient {
public:
    explicit HostSharedBitmapManagerClient(HostSharedBitmapManager* manager);

    ~HostSharedBitmapManagerClient();

    void AllocateSharedBitmapForChild(
        base::ProcessHandle process_handle,
        size_t buffer_size,
        const cc::SharedBitmapId& id,
        base::SharedMemoryHandle* shared_memory_handle);
    void ChildAllocatedSharedBitmap(size_t buffer_size,
        const base::SharedMemoryHandle& handle,
        const cc::SharedBitmapId& id);
    void ChildDeletedSharedBitmap(const cc::SharedBitmapId& id);

private:
    HostSharedBitmapManager* manager_;

    // Lock must be held around access to owned_bitmaps_.
    base::Lock lock_;
    base::hash_set<cc::SharedBitmapId> owned_bitmaps_;

    DISALLOW_COPY_AND_ASSIGN(HostSharedBitmapManagerClient);
};

class CONTENT_EXPORT HostSharedBitmapManager
    : public cc::SharedBitmapManager,
      public base::trace_event::MemoryDumpProvider {
public:
    HostSharedBitmapManager();
    ~HostSharedBitmapManager() override;

    static HostSharedBitmapManager* current();

    // cc::SharedBitmapManager implementation.
    std::unique_ptr<cc::SharedBitmap> AllocateSharedBitmap(
        const gfx::Size& size) override;
    std::unique_ptr<cc::SharedBitmap> GetSharedBitmapFromId(
        const gfx::Size& size,
        const cc::SharedBitmapId&) override;

    // base::trace_event::MemoryDumpProvider implementation.
    bool OnMemoryDump(const base::trace_event::MemoryDumpArgs& args,
        base::trace_event::ProcessMemoryDump* pmd) override;

    size_t AllocatedBitmapCount() const;

    void FreeSharedMemoryFromMap(const cc::SharedBitmapId& id);

private:
    friend class HostSharedBitmapManagerClient;

    void AllocateSharedBitmapForChild(
        base::ProcessHandle process_handle,
        size_t buffer_size,
        const cc::SharedBitmapId& id,
        base::SharedMemoryHandle* shared_memory_handle);
    bool ChildAllocatedSharedBitmap(size_t buffer_size,
        const base::SharedMemoryHandle& handle,
        const cc::SharedBitmapId& id);
    void ChildDeletedSharedBitmap(const cc::SharedBitmapId& id);

    mutable base::Lock lock_;

    typedef base::hash_map<cc::SharedBitmapId, scoped_refptr<BitmapData>>
        BitmapMap;
    BitmapMap handle_map_;

    DISALLOW_COPY_AND_ASSIGN(HostSharedBitmapManager);
};

} // namespace content

#endif // CONTENT_COMMON_HOST_SHARED_BITMAP_MANAGER_H_
